No, corns do not need to soak on a regular basis. The only time they would need to soak is when they are having a bad shed, and then you would probably have to put them into a soaking container. If a corn is soaking on a regular basis, then you need to check it for problems, such as mites or too high temperatures that the snake is trying to get away from.
It is entirely possible to get a bad pinky. Perhaps the pet shop kept their mice on cedar or pine or had no pest strips in the cages, that would definitely affect your snake. Or perhaps the pinky is too old, if you are talking about frozen. Or perhaps you refroze the pinky after it was out of the freezer too long. I would not recommend refreezing food items, by the way, but some people do it.
Pictures on the outside of your tank should not affect the snake at all. Perhaps if there was a picture of a predator on there, MAYBE the snake MIGHT notice it, but if you are talking about scenic pictures, enjoy the view. I think that the snake enjoys having the privacy more than the actual pictures, as being in a big glass house can make anyone nervous.
Hope some of this helps. It is just my opinion.
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sue